1. Field of the Invention
The present invention relates to an insertion support system for supporting insertion of an endoscope.
2. Description of the Related Art
In recent years, diagnosis using an image has been widely performed. For example, a cross-sectional image of a subject is captured by using an X-ray CT (Computed Tomography) apparatus or the like to obtain three-dimensional image data of the subject. The obtained three-dimensional image data is then used for diagnosing an affected area.
The CT apparatus continuously performs X-ray irradiation and detection in a direction of the body axis of the subject while continuously rotating the subject. Thereby, spiral and continuous scanning (i.e., helical scanning) is performed for a three-dimensional region in the subject, and a three-dimensional image is produced from successive cross-sectional slice images of the three-dimensional region.
Such three-dimensional images include a three-dimensional image of the bronchi of the lungs. The three-dimensional image of the bronchi is used for three-dimensionally locating the position of an abnormal area suspected to contain lung cancer, for example. Then, to examine the abnormal area through a biopsy, a bronchoscope is inserted and a tissue sample is obtained by using a biopsy needle, biopsy forceps, or the like which is protruded from a distal end of the bronchoscope.
In a duct within the body that branches in multiple stages, such as the bronchi, if the abnormal area is located near a periphery of a branch, it is difficult to make the distal end of the endoscope correctly reach a target location within a short time period. Therefore, Japanese Unexamined Patent Application Publication No. 2000-135215, for example, proposes an apparatus which navigates the bronchoscope to the target location by producing a three-dimensional image of the duct within the subject on the basis of image data of the three-dimensional region in the subject, determining a route leading to a target point along the duct on the three-dimensional image, producing a virtual endoscope image of the duct along the route based on the image data, and then displaying the virtual endoscope image.